(1) Field of the Invention
The present inventions relate generally to thermal imaging systems and, more particularly, to a thermal imaging system having an improved thermal image generator.
(2) Description of the Prior Art
Infrared and other thermal-related detection devices have become increasingly important, particularly in combat. Since technology facilitates the detection of heat in the battleground, there is an increasing need for training soldiers in identifying enemy versus friendly combatants. One of the challenges facing soldiers in the field who employ heat detection devices such as infrared detectors, is that the identity of a target is not readily discernible based on the mere existence of a heat signature. For example, animals, vehicles and random mechanical devices can all emit heat and therefore present themselves as a potential target.
The detection of humans is not necessarily straight forward either. A human body emits various levels of heat depending on the area of the body. For example, the top of the head emits less heat than the armpit region. These variations in temperature can make the heat signature less than straight forward. Moreover, human heat signatures vary according to the ambient temperature. While one would expect more heat to be emitted in higher ambient temperatures, it is also found that certain regions of the body emit a disproportionally high amount of heat in higher temperatures. Accordingly, a human heat signature in one ambient temperature may vary greatly from an emitted heat signature in another temperature.
While it is beneficial to train soldiers to detect human versus non-human heat signatures, and to train soldiers in detecting human heat signatures in various ambient temperatures, it is also critically important to train soldiers in differentiating one human heat signature from another. When a human that is being detected by infrared detectors is holding or carrying a weapon or other equipment, the resulting heat signature is characterized by a “cold spot” in the image, which corresponds with where the equipment is blocking the body heat. This characteristic in the heat signature is useful in identifying friendly versus enemy soldier where the object causing the heat interference is characteristic to either the friendly or the enemy soldier. For example, a soldier carrying an AK-47 or RPG could be differentiated from U.S. or NATO soldiers who carry different weaponry and other equipment.
Thus, there remains a need for a new and improved thermal imaging system having a thermal image generator including a structure having a surface with at least three heating zones while, at the same time, is adapted to varying the thermal output of the thermal image generator.